That’s normal, your black probe is connected at the wrong location.
Connect the negative probe of your multimeter next to where the red probe is connected.
Turn your pots 1/2 way.
Thanks
Eric
Connect the negative probe of your multimeter next to where the red probe is connected.
Turn your pots 1/2 way.
Thanks
Eric
With a little time and adjustment I’ve gotten both channels stable, this is my first build! I super stoked to listen to it.
Really love the look of the exposed board. I’ll probably mount it on a wooden case with speaker connections, like some other build I’ve seen.
Really love the look of the exposed board. I’ll probably mount it on a wooden case with speaker connections, like some other build I’ve seen.
Yes, providing it is otherwise suitably rated. The cap sees only a few hundred millivolts across it.
Hi all,
have any of you ever swapped the 2SK370 for the 2SK170 ?
If so, was there a change in sound?
In which IDSS range should the 2SK170 / 2SJ74 be?
have any of you ever swapped the 2SK370 for the 2SK170 ?
If so, was there a change in sound?
In which IDSS range should the 2SK170 / 2SJ74 be?
370 - 170: same part, different case, thus different dissipation figure
as I see it, you need at least 5mA Idss JFets
as I see it, you need at least 5mA Idss JFets
I have this amp on sale as an integrated amp if anyone is interested with a very nice chassis - https://www.diyaudio.com/community/threads/aca-mini-as-integrated-amp.403777/#post-7464835
Hi all,
a second ACA mini kid in the house and a new design for the housing .. now we can try both in the "parallel mode". 🙂
Ok, the LED still needs to be aligned and set a little darker.
a second ACA mini kid in the house and a new design for the housing .. now we can try both in the "parallel mode". 🙂
Ok, the LED still needs to be aligned and set a little darker.
I was fortunate to win an assembled ACA Mini at this years Burning Amp Festival. Gonna plug it in today! I have a question. I have only read up to page 16 of this thread so far, so I apologize if this has already been answered. Is the ACA Mini in phase at the output (compared to the input) or out of phase? I biamp and plan on using this amp for the high frequencies, in conjunction with an amp on the bass that I know is in phase.
You might want to read Nelson's original article. It has everything you need to know and is only 17 pages with lots of graphs. 🙂
Took awhile to bias the amp, probably because I was too ham-fisted with the adjustments. Just put it in the rack, replacing an Icepower 50ASX2SE class D amp, which I would call a 20watt/channel into 8 ohms amp based upon the published graphs. The ACA is connected to Fostex 166EN full range drivers crossed over at 1200 hz to 12 inch woofers. The woofers are powered by an LM4780 chip amp with a regulated power supply. Still have to fiddle with the balance between low and high. Got a question for people who have some experience with the ACA. Do you leave yours on all the time? If you don't, does it maintain the correct bias when you turn it back on? How long does it take to get back to stable operating temperature?
I power mine up about 15 minutes prior to use. I've been powering some older ADS L620 speakers with plenty of "umpf" for my taste. I will say that local temps and forced convective cooling from local drafts will affect the bias if you're actively measuring it, however, I don't think I can perceive the differences in sound, so I don't bother changing anything bias wise since my first attempt. It sounds really great for what it is and I couldn't be happier with the compact and affordable design. Thanks so much Mr. Pass and all those who helped for another great DIY amp project!
-Dan
-Dan
Now... this might be nuts, but I am, so let's skip that part. 
I am also a huge fan of this little monster. It plays beatifully, it's loud enough, and it's good for my electricity-bill.
I know I can't make this baby perform like an F4, but I would like to try nudging it a bit, to see if I could add just the tiniest bit of xtra 'grip'.
So... would this work, or would I need to add some gate-resistors when parallelling outputs?
Thank you!
I am also a huge fan of this little monster. It plays beatifully, it's loud enough, and it's good for my electricity-bill.
I know I can't make this baby perform like an F4, but I would like to try nudging it a bit, to see if I could add just the tiniest bit of xtra 'grip'.
So... would this work, or would I need to add some gate-resistors when parallelling outputs?
Thank you!
Attachments
having gate resistors is safety measure
except in cases when you exactly know what you're doing and why going without them
note - sum Iq for circuit above is measure of your intentions
except in cases when you exactly know what you're doing and why going without them
note - sum Iq for circuit above is measure of your intentions